Phobos orbits mars in 27,553 s at a distance of 9.378 × 106 m. what is the mass of mars? 2.58 × 1011 kg 2.05 × 1023 kg 6.43 × 1023 kg 1.09 × 1030 kg

Explanation:

       Phobos orbits Mars in a circular path. So, there must some force acting as centripetal force to maintain the circular path. Gravitational force due to mars takes this role of Centripetal Force.

       So, Gravitational Force = Centripetal Force

is the Gravitational constant, is the mass of Mars, is the mass of Phobos, is the velocity of Phobos, is the Radius of orbit, is the Time period.

∴ Mass of Mars =

electromagnetic shielding is the practice of reducing the electromagnetic field in a space by blocking the field with barriers made of conductive or magnetic materials. shielding is typically applied to enclosures to isolate electrical devices from their surroundings, and to cables to isolate wires from the environment through which the cable runs. electromagnetic shielding that blocks radio frequency electromagnetic radiation is also known as rf shielding.

the shielding can reduce the coupling of radio waves, electromagnetic fields and electrostatic fields. a conductive enclosure used to block electrostatic fields is also known as a faraday cage. the amount of reduction depends very much upon the material used, its thickness, the size of the shielded volume and the frequency of the fields of interest and the size, shape and orientation of apertures in a shield to an incident electromagnetic

from wikipedia

force required to detach it is given by

charges are taken to be fundamental charge

now we have

so above is the minimum distance at which it will detach